#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <uv.h>

uv_loop_t *loop;
uv_udp_t send_socket;
uv_udp_t recv_socket;

void alloc_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) {
  buf->base = malloc(suggested_size);
  buf->len = suggested_size;
}

void on_read(uv_udp_t *req, ssize_t nread, const uv_buf_t *buf, const struct sockaddr *addr, unsigned flags) {
    if (nread < 0) {
        fprintf(stderr, "Read error %s\n", uv_err_name(nread));
        uv_close((uv_handle_t*) req, NULL);
        free(buf->base);
        return;
    }

    char sender[17] = { 0 };
    uv_ip4_name((const struct sockaddr_in*) addr, sender, 16);
    fprintf(stderr, "Recv from %s\n", sender);

    // ... DHCP specific code
    unsigned int *as_integer = (unsigned int*)buf->base;
    unsigned int ipbin = ntohl(as_integer[4]);
    unsigned char ip[4] = {0};
    int i;
    for (i = 0; i < 4; i++)
        ip[i] = (ipbin >> i*8) & 0xff;
    fprintf(stderr, "Offered IP %d.%d.%d.%d\n", ip[3], ip[2], ip[1], ip[0]);

    free(buf->base);
    uv_udp_recv_stop(req);
}

uv_buf_t make_discover_msg() {
    uv_buf_t buffer;
    
    char text[] = "hello?? :)\0";
    buffer = uv_buf_init(&text[0], sizeof(text) - 1);


    /* // BOOTREQUEST */
    /* buffer.base[0] = 0x1; */
    /* // HTYPE ethernet */
    /* buffer.base[1] = 0x1; */
    /* // HLEN */
    /* buffer.base[2] = 0x6; */
    /* // HOPS */
    /* buffer.base[3] = 0x0; */
    /* // XID 4 bytes */
    /* buffer.base[4] = (unsigned int) random(); */
    /* // SECS */
    /* buffer.base[8] = 0x0; */
    /* // FLAGS */
    /* buffer.base[10] = 0x80; */
    /* // CIADDR 12-15 is all zeros */
    /* // YIADDR 16-19 is all zeros */
    /* // SIADDR 20-23 is all zeros */
    /* // GIADDR 24-27 is all zeros */
    /* // CHADDR 28-43 is the MAC address, use your own */
    /* buffer.base[28] = 0xe4; */
    /* buffer.base[29] = 0xce; */
    /* buffer.base[30] = 0x8f; */
    /* buffer.base[31] = 0x13; */
    /* buffer.base[32] = 0xf6; */
    /* buffer.base[33] = 0xd4; */
    /* // SNAME 64 bytes zero */
    /* // FILE 128 bytes zero */
    /* // OPTIONS */
    /* // - magic cookie */
    /* buffer.base[236] = 99; */
    /* buffer.base[237] = 130; */
    /* buffer.base[238] = 83; */
    /* buffer.base[239] = 99; */

    /* // DHCP Message type */
    /* buffer.base[240] = 53; */
    /* buffer.base[241] = 1; */
    /* buffer.base[242] = 1; // DHCPDISCOVER */

    /* // DHCP Parameter request list */
    /* buffer.base[243] = 55; */
    /* buffer.base[244] = 4; */
    /* buffer.base[245] = 1; */
    /* buffer.base[246] = 3; */
    /* buffer.base[247] = 15; */
    /* buffer.base[248] = 6; */

    return buffer;
}


void on_send2(uv_udp_send_t *req, int status) 
{
    if (status) {
        fprintf(stderr, "Send error %s\n", uv_strerror(status));
        return;
    }
    printf("message sent!");
}



void on_send(uv_udp_send_t *req, int status) 
{
    if (status) {
        fprintf(stderr, "Send error %s\n", uv_strerror(status));
        return;
    }
    printf("message sent!");
}

void udpHeartBeatCb(uv_timer_t *handle)
{
    printf("hello\n" );



  uv_udp_send_t *req2 = (uv_udp_send_t*)malloc(sizeof(uv_udp_send_t));

  uv_buf_t buffer;
  char text[] = "hello?? :)\0";
  buffer = uv_buf_init(&text[0], sizeof(text) - 1);

    struct sockaddr_in send2;
    printf("%d", uv_ip4_addr("255.255.255.255", 23232, &send2));
  uv_udp_send(req2, &send_socket, &buffer, 1, (const struct sockaddr *)&send2, on_send);

}


int main() 
{
    loop = uv_default_loop();

    /* uv_udp_init(loop, &recv_socket); */
    /* struct sockaddr_in recv_addr; */
    /* uv_ip4_addr("0.0.0.0", 68, &recv_addr); */
    /* uv_udp_bind(&recv_socket, (const struct sockaddr *)&recv_addr, UV_UDP_REUSEADDR); */

    uv_udp_init(loop, &send_socket);
    int fd = 0;
    uv_fileno((uv_handle_t *)&send_socket, &fd);
    struct sockaddr_in broadcast_addr;
    uv_ip4_addr("0.0.0.0", 23232, &broadcast_addr);
    uv_udp_bind(&send_socket, (const struct sockaddr *)&broadcast_addr, UV_UDP_REUSEADDR);
    uv_udp_set_broadcast(&send_socket, 1);
    //uv_udp_recv_start(&send_socket, alloc_buffer, on_read);


    struct sockaddr_in send_addr;
    printf("%d", uv_ip4_addr("255.255.255.255", 23232, &send_addr));
    
    uv_udp_send_t send_req;
    uv_buf_t discover_msg = make_discover_msg();
    uv_udp_send(&send_req, &send_socket, &discover_msg, 1, (const struct sockaddr *)&send_addr, on_send);



    struct sockaddr_in send2;
    printf("%d", uv_ip4_addr("255.255.255.255", 23232, &send2));

    uv_udp_send_t req2;
    uv_buf_t discover_msg1 = make_discover_msg();
    uv_udp_send(&req2, &send_socket, &discover_msg1, 1, (const struct sockaddr *)&send2, on_send2);

    uv_timer_t *heartBeatTimer = (uv_timer_t*)malloc(sizeof(uv_timer_t));
    uv_timer_init(loop, heartBeatTimer);
    uv_timer_start(heartBeatTimer, udpHeartBeatCb, 500, 100);


    return uv_run(loop, UV_RUN_DEFAULT);
}












